Listen to Khan Academy — Free Audio for K-12 Lessons
CastReader adds text-to-speech to Khan Academy. Click play on any math article, science lesson, SAT prep page, or AP review — it reads aloud with paragraph highlighting and natural AI voices. Free for students, parents, and teachers.
Why CastReader is Perfect for Khan Academy
Built for students who learn better by ear — and parents helping with homework
The Problem
Free Lessons, but Many Articles Are Pure Text
Khan Academy is famous for video lessons, but a huge portion of its content is text-based articles — algebra walk-throughs, biology concepts, US history readings, SAT reading passages, MCAT primers, AP review pages. For students with ADHD, dyslexia, or anyone who absorbs better by ear, screen reading is a real obstacle. None of it has built-in audio.
ADHD & Dyslexia Friendly
Reading + Listening = Better Focus
Research shows that combining audio and visual input — reading along while listening — significantly improves focus and retention for students with ADHD and dyslexia. Each paragraph highlights as it's read, anchoring attention on the current sentence. The dual-channel approach is exactly what Khan Academy's mission of accessible education needs.
K-12 Friendly Voices
Natural AI Voices, Not Robotic
Khan Academy serves elementary through college learners. Robotic TTS turns kids off. CastReader uses natural AI voices that sound like a friendly tutor — clear pronunciation of math terms, fractions, scientific names, historical figures. Kids will actually listen.
Test Prep
SAT, MCAT, AP Reading Passages by Ear
Khan Academy's official SAT, MCAT, and AP prep includes long reading passages, practice questions, and explanations. Listen during practice — train your ear for SAT reading comprehension, hear MCAT biology passages while exercising, replay AP US history at slower speeds for retention. Test prep finally fits into commute time.
100% Free
Free Mission, Free Tool
Khan Academy is non-profit and free for everyone. CastReader is also completely free. No signup, no subscription, no limits. Together, they remove cost as a barrier to learning — exactly what both projects stand for.
Khan Academy Text to Speech in 2026: Audio for K-12 Learning
Khan Academy is one of the most beloved free education platforms in the world — 130+ million registered learners across 190+ countries. Founded by Sal Khan in 2008, it covers K-12 math (kindergarten through calculus), science, computing, economics, humanities, and official prep for SAT, MCAT, AP exams, LSAT, GMAT, and Praxis. Every lesson is free, and the non-profit mission is uncompromising: 'a free, world-class education for anyone, anywhere.'
While Khan Academy's video tutorials get the spotlight, a huge fraction of the content is text articles. Math articles walk through proofs and methods step by step. Science lessons explain photosynthesis, plate tectonics, the periodic table. US History articles cover wars, presidents, civil rights. SAT and MCAT prep includes long reading passages with comprehension questions. AP courses use article-based readings between video lectures. None of this text content has built-in audio.
CastReader adds text-to-speech to Khan Academy as a free Chrome extension. Open any article on khanacademy.org — a calculus walk-through, a biology lesson, an SAT reading passage — click the extension icon, and listen to it read aloud with natural AI voices. Each paragraph highlights as it's spoken, so students can follow visually while listening. The dual-channel input is especially powerful for students with ADHD, dyslexia, or anyone who learns better by ear.
Parents helping with homework benefit too. Reading a 5th-grader's geometry article aloud while checking their work? CastReader reads it for you, accurately, with proper math vocabulary. Walking through an AP US History reading with your high schooler? CastReader handles narration so you can focus on discussion. Teachers can use CastReader during lesson prep to scan readings while doing other work.
CastReader supports 40+ languages with natural AI voices. Khan Academy now offers content in 50+ languages — Spanish, Portuguese, French, Hindi, Arabic, Mandarin, and more — and CastReader reads in the page's language. ESL students learning English from Khan Academy, or native English speakers studying Spanish on the platform, both benefit. Combined with adjustable speed from 0.5x to 3x, CastReader makes Khan Academy's free education even more accessible.
Frequently Asked Questions
Everything about Khan Academy text to speech
Does Khan Academy have a built-in text-to-speech feature?
No, Khan Academy does not offer built-in text-to-speech. Videos have audio narration, but article-based lessons, SAT/MCAT/AP prep readings, and explanations are text-only. CastReader adds free TTS to any Khan Academy page.
Is CastReader good for students with dyslexia or ADHD?
Yes — this is a primary use case. Reading along while listening (dual-channel input) improves focus and retention for students with ADHD and dyslexia. CastReader highlights each paragraph as it's read, anchoring attention. Combined with Khan Academy's free curriculum, this is a powerful accessibility tool.
Can parents use CastReader to help their kids with homework?
Yes. Parents can play any Khan Academy lesson aloud while their child follows along, or while the parent does other tasks. The natural voices and clear pronunciation handle math terms, scientific names, and historical figures correctly.
Does CastReader work for SAT, MCAT, and AP prep on Khan Academy?
Yes. Khan Academy's official SAT, MCAT, AP, LSAT, GMAT, and Praxis prep includes long reading passages and explanations. CastReader reads all of them aloud — perfect for ear-training during reading comprehension practice or reviewing during commutes.
Is CastReader free for Khan Academy users?
Yes, 100% free. Khan Academy is free, CastReader is free. No signup, no subscription, no usage limits, no in-app purchases.
Can I adjust the speed for younger learners?
Yes. CastReader offers 0.5x to 3x speed. For elementary-age learners, 0.75x or 1.0x is comfortable. For older students reviewing familiar material, 1.5x or 2x speeds up review without losing comprehension.
What languages does CastReader support for Khan Academy?
CastReader supports 40+ languages with natural AI voices. Khan Academy is available in 50+ languages — Spanish, Portuguese, French, Hindi, Arabic, Mandarin — and CastReader reads in whatever language the page is written in.
Does CastReader read math equations correctly?
CastReader reads prose and standard math notation. For complex equations rendered as images or KaTeX, it reads available alt text and surrounding context. The math article's prose explanation — which is most of the content — reads cleanly.
Can CastReader work on Khan Academy Kids?
CastReader works on khanacademy.org in desktop Chrome and Edge browsers. Khan Academy Kids is a separate mobile app — CastReader doesn't work there. For desktop Khan Academy lessons used by older kids, CastReader works fine.
Does CastReader work with other learning platforms besides Khan Academy?
Yes. CastReader works on any website. It supports Khan Academy, Coursera, edX, Udemy, freeCodeCamp, Canvas LMS, AWS Skill Builder, and any other web-based learning platform.
Also Try
Listen to Coursera
Add TTS to Coursera courses from Stanford, Yale, Google
Listen to edX
Add TTS to edX courses from MIT, Harvard, Berkeley
Listen to freeCodeCamp
Add TTS to coding tutorials and articles
TTS for Dyslexia
How TTS helps readers with dyslexia
TTS for ADHD
How TTS helps focus for ADHD readers
TTS for Students
Study more effectively with audio
Start Listening to Khan Academy Now
Completely free. No signup. No limits. Turn every Khan Academy lesson into audio.